Persistent and radiation-induced currents in distorted quantum rings

TL;DR

This paper theoretically examines how distortions in narrow quantum rings influence persistent and radiation-induced currents, revealing that geometrical distortions significantly modify current behaviors under magnetic flux and electromagnetic radiation.

Contribution

It introduces a geometrical potential model for ring distortions and analyzes their effects on both persistent and radiation-induced currents, highlighting new insights into current modulation.

Findings

Distortions smooth persistent current oscillations.

Distortions induce an ac component in radiation-induced currents.

Temperature dependence of persistent current is altered by distortions.

Abstract

Persistent and radiation-induced currents in distorted narrow quantum rings are theoretically investigated. We show that ring distorsions can be described using a geometrical potential term. We analyse the effect of this term on the current induced by a magnetic flux (persistent current) and by a polarized coherent electromagnetic field (radiation-induced current). The strongest effects in persistent currents are observed for distorted rings with a small number of electrons. The distortion smoothes the current oscillations as a function of the magnetic flux and changes the temperature dependence of the current amplitude. For radiation-induced currents, the distortion induces an ac component in the current and affects its dependence on the radiation frequency and intensity.